Types of pain

Pain can be classified in different ways, most common classifications are

1. Based on the pathophysiological mechanism (nociceptive or neuropathic pain)
2. Based on the duration (acute, chronic or sub-classifications)
3. Based on etiology (malignant or non-malignant)
4. Based on the anatomic location of pain

1.Based on pathophysiological mechanism:

Nociceptive pain: This kind of pain develops due to tissue injury that stimulates pain receptors called nociceptors

Neuropathic pain: Caused by injury to nerve cells in the our nervous system

2.Based on duration:

(a) Acute pain: Pain of sudden onset, occurs immediately after an injury and is usually severe in nature.

(b) Chronic pain: This is a pain that continues beyond the normal healing process. It can start as an acute pain but lasts for more than 3 months.

(c) Episodic or recurrent pain: Occurs intermittently over a long period of time and the patient can be pain free in-between episodes (e.g. sickle cell disease).

(d) Breakthrough pain: It is an exacerbation of pain (e.g. acute on top of chronic pain or variations in the level of severity of chronic pain).

(e) End of dose pain: Pain that occurs when medication levels fall in blood to sub-therapeutic levels.

3.Based on etiology:

(a) Malignant pain: Pain associated with cancer. Pain can be caused by the malignancy itself or related treatment (chemotherapy, radiotherapy and surgery).

(b) Non-malignant pain: simply refer to pain not associated with malignancy.

4.The anatomic location:

Pain classified by location (e.g. head, neck or back pain)